Posts Tagged ‘space’

What was Earth like 2.8 billion years ago? The first life was emerging on the planet. The Sun was weaker than it is today, but geologic evidence shows that the climate was as warm (or warmer) than it is today. Was Earth colder because of the weak Sun, or warmer, as geologic evidence suggests? How did this affect how life arose?

A new 3-D model of early Earth suggests that the planet underwent significant changes–from very warm to very cold. Past models were one-dimensional–holding constant the amount of cloud cover or sea ice–to make the calculations easier. But with more advanced computing, researchers at the University of Colorado Boulder were able to make better models of the planet’s climate.

The scientists’ model shows that Earth was periodically covered by glaciers, but the geologic evidence suggests that it was much warmer than that. The calculations show that an atmosphere that contained 6% carbon dioxide would have kept the temperature high enough for life to thrive, but the soil samples show that the carbon dioxide concentration was not that high. So what’s the warming mechanism? Eric Wolf and Brain Toon are still searching for it.

Since the 3-D model takes so much computing time (up to three months for a single calculation), we’ll be waiting a while for the answer.

“The ultimate point of this study is to determine what Earth was like around the time that life arose and during the first half of the planet’s history,” said Toon. “It would have been shrouded by a reddish haze that would have been difficult to see through, and the ocean probably was a greenish color caused by dissolved iron in the oceans. It wasn’t a blue planet by any means.” By the end of the Archean Eon some 2.5 billion year ago, oxygen levels rose quickly, creating an explosion of new life on the planet, he said.

And along the way, better models of Earth’s climate will come out of this study, enhancing scientists’ ability to predict what Earth’s future might look like, and scientists will learn more about the conditions of early Earth, which could help in assessing the habitability potential of other planets.

A team of astronomers led by scientists at the California Institute of Technology have found 18 planets orbiting stars more massive than our Sun. Finding planets is becoming more and more routine with the Kepler telescope, but these planetary discoveries help to answer questions about planetary formation–and raise other questions about planetary orbits.

The scientists focused on stars more than 1.5 times more massive than our Sun. To look for planets, they used the “wobble” method, which looks for shifts in the apparent wavelengths coming from the star. The 18 planets that they found are all larger than Jupiter.

According to John Johnson, assistant professor of astronomy at Caltech, these discoveries support a theory of planet formation. There are two competing explanations for how planets form: a) tiny particles clump together to make a planet and b) large amounts of gas and dust spontaneously collapse into big dense clumps that become planets.

The discovery of these planets supports the first explanation.

If this is the true sequence of events, the characteristics of the resulting planetary system — such as the number and size of the planets, or their orbital shapes — will depend on the mass of the star. For instance, a more massive star would mean a bigger disk, which in turn would mean more material to produce a greater number of giant planets.

So far, as the number of discovered planets has grown, astronomers are finding that stellar mass does seem to be important in determining the prevalence of giant planets. The newly discovered planets further support this pattern — and are therefore consistent with the first theory, the one stating that planets are born from seed particles.

The larger the star, the larger the planets that orbit it.

“It’s nice to see all these converging lines of evidence pointing toward one class of formation mechanisms,” Johnson says.

But there’s another mystery that’s come out of this discovery. The orbits of these 18 newly-discovered large planets are mainly circular. Planets around other Sun-like stars have circular and elliptical orbits. Is there something about the larger stars that make it more likely that planets will have a circular orbit? Or is it just a phenomenon noticed because of the small sample size? Johnson says he’s now trying to find an explanation.

Stay tuned–not only may we find a planet that could harbor life, we could also learn something about the origin of our own solar system!

Learn more about finding planets and the search for extraterrestrial life in the High-Adventure Science investigation, Is there life in space?

NASA technology is being used to find fossil aquifers underneath Earth’s driest deserts. This technology was developed to explore underneath the surface of Mars, to help determine if there might be water on the red planet. Water is a sign that life might be possible.

Why are they using this technology on Earth? We know that there is water on Earth; we know that there is life on Earth.

Firstly, it’s the only way that scientists can “see” underground structures.

“This demonstration is a critical first step that will hopefully lead to large-scale mapping of aquifers, not only improving our ability to quantify groundwater processes, but also helping water managers drill more accurately,” said Muhammad Al-Rashed, director of Kuwait Institute for Scientific Research’s Division of Water Resources.

We might have a lot of water on Earth, but it’s not distributed equally. Knowing the availability of the water supply helps us to use it in a sustainable manner.

Secondly, it’s a good way to study the climactic history of these regions.

“This research will help scientists better understand Earth’s fossil aquifer systems, the approximate number, occurrence and distribution of which remain largely unknown,” said Essam Heggy, research scientist at NASA’s Jet Propulsion Laboratory. “Much of the evidence for climate change in Earth’s deserts lies beneath the surface and is reflected in its groundwater. By mapping desert aquifers with this technology, we can detect layers deposited by ancient geological processes and trace back paleoclimatic conditions that existed thousands of years ago, when many of today’s deserts were wet.”

Previously, climate research has focused on Earth’s polar regions and forests. It is important to study those areas, but arid and semi-arid regions make up a big part of the planet, and they should be studied too.

This is a great story that shows how technology developed for one area of research can often be useful for several other fields of science–all of which are highlighted in our High-Adventure Science investigations!

Pumice, a type of volcanic rock, is so porous that it floats on water, as shown in the picture below.

Now researchers from Oxford University and the University of Western Australia are suggesting that life on Earth could have formed on floating rafts of pumice.

The researchers argue that pumice has a unique set of properties which would have made it an ideal habitat for the earliest organisms that emerged on Earth over 3.5 billion years ago.

‘Not only does pumice float as rafts but it has the highest surface-area-to-volume ratio of any type of rock, is exposed to a variety of conditions, and has the remarkable ability to adsorb metals, organics and phosphates as well as hosting organic catalysts, such as zeolites,’ said Professor Martin Brasier of Oxford University’s Department of Earth Sciences who led the work with David Wacey of the University of Western Australia. ‘Taken together these properties suggest that it could have made an ideal ‘floating laboratory’ for the development of the earliest micro-organisms.’

Floating pumice could have been exposed to lightning, oily residue and metals from hydrothermal vents, and ultraviolet light. All of these conditions have the potential to generate the kinds of chemical reactions that scientists hypothesize created the first living cells.

The scientists plan to test their hypothesis by subjecting pumice rocks with cycles of heat and radiation to see if the process creates molecules associated with life. They also plan to examine the early fossil record for evidence of fossils in pumice.

If scientists can determine how life on Earth began, they’ll be better prepared to search for evidence of life on other planets.

Learn about the search for extraterrestrial life in the High-Adventure Science space investigation.

On September 12, 2011, a team of scientists announced that the HARPS telescope has identified more than 50 new planets; this is the largest number of planets ever announced at once.

The HARPS telescope works by detecting the movement of stars. A star with an orbiting planet will be pulled towards the planet as it orbits. If the star moves toward and away from Earth, this movement can be detected and planets can be discovered.

Astronomers have pointed HARPS at 376 Sun-like stars, and over the past eight years, they have discovered more than 150 new planets. At least one of the newly-discovered planets is potentially habitable; HD85512b is estimated to be only 3.6 times the mass of Earth and it orbits its star within a zone in which liquid water could exist.

The increasing precision of the new HARPS survey now allows the detection of planets under two Earth masses. HARPS is now so sensitive that it can detect radial velocity amplitudes of significantly less than 4 km/hour– less than walking speed.

“The detection of HD 85512 b is far from the limit of HARPS and demonstrates the possibility of discovering other super-Earths in the habitable zones around stars similar to the Sun,” adds Michel Mayor, of the University of Geneva, Switzerland.

This is just the beginning for finding Earth-like planets around other stars!

Astronomers at the California Institute of Technology have discovered that “Snow White,” a dwarf planet officially named 2007 OR10, is actually red. Time to come up with another name! But why was it called Snow White to begin with?

It was originally called Snow White because Mike Brown, a professor of planetary astronomy at Caltech, had guessed that it was an icy body formed by a breakup of another dwarf planet. Since he thought the planet would be icy and water ice appears to be white, the name fit.

Dr. Brown and his team have discovered that the little planet known as Snow White is actually red. And it is covered with water ice, which is usually white. So what makes this little planet red?

The explanation is probably in Snow White’s disappearing atmosphere. In 2002, Dr. Brown helped to discover a similar dwarf planet, Quaoar.

Quaoar was covered with volcanoes that spewed an icy slush. Quaoar was too small to hold on to its atmosphere, so it has slowly drifted away into space. What was left behind was some methane, the heaviest gas thought to have been in its atmosphere. The methane, after being exposed to space radiation, combined into long hydrocarbon chains. The hydrocarbon chains rest on the icy surface, giving Quaoar a rosy hue.

The spectrum of “Snow White” looks similar to the spectrum of Quaoar, an indication that the planets’ atmospheric compositions may be the same.

“That combination — red and water — says to me, ‘methane,'” Brown explains. “We’re basically looking at the last gasp of Snow White. For four and a half billion years, Snow White has been sitting out there, slowly losing its atmosphere, and now there’s just a little bit left.”

Mike Brown doesn’t yet know that Snow White has methane; there’s no evidence, other than the comparison with Quaoar. It will take more investigation, with a larger telescope, to determine that for sure.

And now that the astronomy community has determined that Snow White is an interesting object to study, it needs a real name.

Before the discovery of water ice and the possibility of methane, “2007 OR10″ might have sufficed for the astronomy community, since it didn’t seem noteworthy enough to warrant an official name. “We didn’t know Snow White was interesting,” Brown says. “Now we know it’s worth studying.”

That’s science–there’s always more to discover, even when it seems like all of the interesting discoveries have already been made.

Stay tuned to see what they re-name “Snow White.”

Explore how spectroscopy is used to determine the atmospheric composition of distant planets in our space investigation.

Formaldehyde has many industrial uses–in particle board, plywood, carpet, and adhesives, to name just a few. Formaldehyde is toxic to life–the reason that it’s used as a disinfectant–and the reason that many countries have banned the use of formaldehyde in furniture and housing materials.

But formaldehyde may well have formed the basis for life in our solar system.

New research, published in the Proceedings of the National Academy of Sciences on April 4, 2011, shows that complex organic solids were likely made from formaldehyde in the primitive solar system.

George Cody, Conel Alexander, and Larry Nittler did experiments to try to make the type of organic matter found in meteorites. When they started their reactions with formaldehyde, they found that the organic material that was created was similar to the organic material in the meteorites and also similar to the organic material found in a comet that NASA had sampled.

“We may owe our existence on this planet to interstellar formaldehyde,” Cody said. “And what’s ironic about it is that formaldehyde is poisonous to life on Earth.”

Formaldehyde is relatively abundant throughout the galaxy, making it possible that life could form in other solar systems in the same way that it formed in this solar system.

“Within the next 6 to 12 months, I suspect we’ll be able to detect and verify and announce planets that at least have the size of our own Earth.”

–Dr. Geoffrey Marcy, University of California Berkeley

“This changes our understanding of our role in the universe. We, in some sense, are not alone in terms of being a planet circulating around a star. We now realize, that potentially, there could be thousands, billions of planets right in our own back yard, right in our own Milky Way galaxy. This is a game changer.”

–Dr. Michio Kaku

The recent news release about Kepler-10b has put NASA into the spotlight again.

Click on the link below to watch a really great video from The Wall Street Journal about astronomers’ latest discoveries of new planets and how they’ll know if they’ve found a planet that can support life.

NASA scientists have deduced that the newly-discovered planet Kepler-10b is 4.6 times more massive than Earth with an average density of 8.8 grams per cubic centimeter, about the same density as bronze. How did they learn this from a telescope that detects light changes? (See earlier post about Kepler-10b’s discovery.)

It turns out that knowing a lot about the star helps to learn a lot about its orbiting planets. Scientists had previously studied Kepler-10 in great detail, using starquakes (much like earthquakes on Earth) to learn about the interior structure of Kepler-10. Having this information made it possible to calculate the mass and density of its orbiting planet.

Finding new planets is very exciting, but it’s far more exciting to be able to infer what those planets are like. It might not be as exciting to do the basic research to characterize stars as it is to find planets, but it’s necessary to know about the stars to fully describe the planets. Just as in all scientific fields, the latest breakthrough discoveries are always built on a strong foundation of basic research.

On January 10, 2011, NASA confirmed that the Kepler space telescope had found its first rocky planet, named Kepler-10b. Kepler-10b is really small, the smallest planet yet discovered outside of our solar system, at 1.4 times the size of Earth.

The discovery of Kepler-10b was made possible by some major advances in technology:

the ability to put the Kepler telescope into space

an ultra-precise photometer on the Kepler telescope that allows it to measure tiny decreases in stars’ brightnesses

the huge analytical power of computers needed to decipher the signal from the noise

Although Kepler-10b isn’t in the habitable zone of its star, Kepler-10, it does show us the power of technology to find more small planets, some of which may be more Earth-like and have the ability to support life.